There's a good chance that Spain will be the preferred bid for the 2030 Winter Olympics which will make it difficult to award them the 2036 Summer Olympics. If not, then I suspect Canada will win the 2030 bid so they would be out for 2036.
I don't think the IOC is dumb enough to award Germany the 2036 Olympics, the connection to 1936 would create a media frenzy.
I do think a nation from Europe will be the next host. From what I hear, Great Britain and Italy seem to show the most interest and I feel they are just far enough from last hosting the Summer/Winter games to be at least considered. As for other nations coming out of nowhere, Russia is a non-starter for obvious reasons and Ukraine is pre-occupied right now, it's too soon for France so that leaves us with the Netherlands, Hungary or Poland if one of them has the will to put up a serious bid. Turkey is always interested in hosting, but I don't think the IOC will pick them unless none of the big nation decide to submit a bid.
Outside of Europe, China would probably be the favourite, South Korea could make a decent case if they really wanted to while Egypt will bring the 1st games in Africa vibe.